1. Field of the Invention
The invention relates to a press pad made of asbestos-free material for a great variety of different types of high-pressure and low-pressure presses. Such presses include short-cycle and multi-platen presses for the lamination of sheets of particle-board with sheets of, for example, MELAMINE (molded melamine-formaldehyde resins), etc., high-pressure presses for the production of high-pressure laminates, and other presses for many other applications. This list is exemplary only and is not intended to be exhaustive.
2. Description of the Related Art
The presses mentioned above are mechanical systems which work with different temperatures and pressures. The presses themselves, as well as the materials to be pressed, have more or less large tolerances. In such presses, press pads have the task of compensating for these tolerances and of transferring the pressing pressure uniformly to the entire surface of the materials to be pressed.
Additionally, press pads must have good thermal conductivity so that the heat which is necessary for the manufacture of the final product, usually a laminate, is transmitted with the smallest possible loss of heat.
Press pads must not only compensate for the mentioned tolerances and have good thermal conductivity, but they must also be able to withstand the sometimes considerable pressures and temperatures in the presses, and they must retain these characteristics over prolonged periods.
The following types of press pads are predominantly used at the present time: pads made of asbestos-free yarns comprising metal threads, identical yarns in combination with pure metal yarn, pure metal pads, kraft papers, and press pads with fleece lining (see German Published Patent Application No. G 92 03 498.5). This list is exemplary only and is not intended to be exhaustive.
It is an object of the present invention to provide a press pad which, compared to the press pads used in the past, is characterized by a particularly marked improvement of the padding action and, at the same time, good heat transfer.
It is another object of the present invention to provide a press pad that has a combination of padding action and heat transfer characteristics that may be varied while continuing to exhibit a particularly marked improvement of the padding action and, at the same time, good heat transfer.